Effect of contact force on diode characteristics of Rh/epitaxial graphene/n-SiC

Abstract The contact force dependence of the electrical characteristics of metal/epitaxial graphene/n-SiC diodes was investigated using conductive contact-mode scanning probe microscopy (SPM) with an Rh-coated conductive nanoprobe. Graphene nano-islands formed by the thermal decomposition method were used. The measured electrical characteristics showed excellent rectification behavior. The on-off ratio improved with increasing contact force. The estimated Schottky barrier height decreased with increasing contact force. In the low contact force regime (<100 nN), Fowler-Nordheim tunneling (FNT) phenomena were observed, as the carbon layers (graphene and buffer layer) acted as a tunneling barrier.